Exposure and accumulation of cadmium in populations from Japan, the United States, and Sweden

Studies were carried out in Japan, United States, and Sweden regarding comparability of analytical methods for cadmium, daily intake of cadmium via food, daily amount of cadmium in feces, concentrations of cadmium in different tissues and the body burden of cadmium, urinary excretion of cadmium and cadmium concentrations in blood. It was found that the cadmium intake via food among adults is about 35 μg/day in Japan (Tokyo) and about 17 μg/day in the U.S. (Dallas) and Sweden (Stockholm). It varies with age in a way similar to calorie intake. Body burden increases rapidly with age. The half-time of cadmium is longer in muscles than in liver or kidneys. In the cross-sectional population samples studied (smokers and nonsmokers mixed) the average cadmium body burden at age 45 was about 21 mg in Japan, 9 mg in the U.S., and 6 mg in Sweden. Among nonsmokers in the U.S. and Sweden the body burden at age 45 was about 5–6 mg. The difference in average body burden for smokers and nonsmokers is explained by differences in smoking habits. Cadmium excretion in urine was closely correlated with body burden and about 0.005–0.01% of body burden is excreted daily in urine. Cadmium concentration in the blood was a good indicator of average recent intake over a 3-month period. Neither blood cadmium nor urine cadmium changed immediately after an increase of exposure level.